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Molecular simulations of the structure and thermal transport of high alumina aluminosilicate molten core glass fiber
Author(s) -
Greenberg Bennett,
Garofalini Stephen H.
Publication year - 2018
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.15471
Subject(s) - aluminosilicate , materials science , molecular dynamics , thermal , amorphous solid , gyration , radius of gyration , coordination number , chemical physics , crystallography , thermodynamics , ion , composite material , chemistry , polymer , computational chemistry , catalysis , biochemistry , physics , geometry , mathematics , organic chemistry
The atomistic structure and phonon transport in aluminosilicate glasses made via an interfacial mixing model of the Molten Core process were studied using molecular dynamics simulations. In the simulations, silica glass was brought in contact with different size alumina crystals (to afford core glasses with 4, 18, 24, 29, and 41 mole% alumina concentrations), followed by a melt‐quench process to enable mixing of the phases. The atomistic structure of the resulting glasses and radius of gyration calculations of resultant Al‐O‐Al connected clusters were evaluated. Variation in the 1‐dimensional thermal transport in each glass was also determined and showed that increased alumina concentration in the glasses resulted in increased transport of thermal energy. Results of the structural analyses showed a double peak in the Al‐Al pair distribution function, with the short‐distance peak indicative of edge‐sharing Al‐O‐Al‐O bonding and a longer distance peak of Al‐O‐Al bonding that is not indicative of edge‐sharing structures. The ratio of the first Al‐Al peak to the second Al‐Al peak varied inversely with the thermal transport behavior. An increased radius of gyration of Al‐O‐Al connectivity occurred with increasing alumina concentration, providing a mechanism for the increased thermal transport. Nanosegregation was also observed. Interconnectivity between Al ions created isolated Al‐O‐Al bonded clusters at low alumina concentrations with lower thermal transport than the high alumina glasses, whereas the latter showed a percolated network of Al‐O‐Al bonds that increased thermal transport.